How would I go about remapping this UV
If you have imported the mesh, then maybe it's just how this UV is supposed to be used.
It looks like the problematic area is where there's supposed to be hairs. My guess is that the texture you're using isn't used on that area.

Then, either it's a matter of different UV sets, in which case you just might check in your object's Data tab if you have several UVs, and unse them accordingly in your material :


Either you just have to select those faces, and assign them to another material :


Or maybe both.